Pyrromycinones

The trisaccharide chain in Cinerubin A, an anthracycline antibiotic with antimitotic activity, has been replaced by a poly(ethylene glycol) The resulting poly(ethylene oxide)-bound e-pyrromycinone is readily soluble in water and exhibits full biological activity. In this case, the hydrophilic poly(ethylene oxide) chain appears to be perfectly suitable to simulate the physicochemical properties of the oligosaccharide chain. 

In contrast to the anthracyclinones [21,22], the more polar glycosides usually do not give reliable mass spectra on electron impact ionization (EI-MS). In cases such as cinerubin A (23), where aromatization can take place easily, the sugar residues are split off completely, and the bisanhydro-aglycones are formed. In the spectrum of 23, the signal of ]-pyrromycinone (24) is detected (m/z = 392). 

Trihydroxylated anthracycHne and anthracycUnones can be divided into four majors classes, based on the position of the OH groups 1,4,6-trihydroxyan-thracyclinones belong in majority to the pyrromycinone type the 1,4,11- and the 4,6,11-trihydroxyquinones are usually summarized as rhodomycinones. 

Red powder. Mp 180.5°. Shows same gross strueture as ej-Pyrromycinone. Aglycone, 10-epimer, 7-deoxy Resomydn A... 

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